What do you put your LO’s to sleep in?

Trista • Girl mom of 2 under 2💜

I live in the Midwest and she currently wears this to bed (arms out of course). She’s about to grow out of it and I’m looking for advice on what to do next? I put thin long sleeve footed pajamas underneath it for now but as it gets colder I’m worried she won’t be warm enough. So, should I forget the sleep sack completely and just put her in fleece pajamas? Should I get the next size up of the sack? This company also sells a sack that has the feet out too. 🤷🏻‍♀️ Looking for suggestions 😉